For the chicken:

2 Tbsp butter
1 Tbsp olive oil
2 lbs boneless, skinless chicken breasts or thighs, cut into 2” pieces
Salt and pepper
1 onion, diced
3 celery stalks, trimmed and diced
3 carrots, peeled and sliced
3 sprigs fresh thyme, or ½ tsp dried thyme
¼ cup all-purpose flour
2 ½ cups chicken stock
1 cup frozen peas
Juice of 1 lemon
For the dumplings:

¾ cup all-purpose flour
2 tsp baking powder
1 tsp dried dill
½ tsp salt
1 Tbsp melted butter
½ cup milk